Battery can

Abstract

Aspects of the present disclosure involve various battery can designs. In general, the battery can design includes two fitted surfaces oriented opposite each other and seam welded together to form an enclosure in which a battery stack is located. To form the enclosure, the two fitted surfaces are welded together along the large perimeter. Other swelling-resisting advantages may also be achieved utilizing the battery can design described herein including, but not limited to, the ability to modify one or more can wall thicknesses to control a pressure applied to the battery stack by the can, overall reduction in wall thickness of the can through the use of stronger materials for the can surfaces, additional supports structures included within the can design, and/or bossing or other localized thinning of surfaces of the can.

What is claimed is: 
     
       1. A battery can assembly comprising:
 a first portion formed of metal comprising a first surface; 
 a second portion formed of metal comprising a second surface surrounded by a wall extending from the second surface; and 
 a battery stack disposed between the first and second portion;
 wherein the walls of the second portion are welded to the first surface of the first portion to form a seam around a perimeter of the battery can assembly to enclose the battery stack; and 
 wherein the second surface of the second portion forms a plurality of indentations that extend into an interior of the battery can assembly to increase the structural rigidity of the second surface. 
 
 
     
     
       2. The battery can assembly of  claim 1  wherein the wall comprises at least one electrical connection and an electrolyte fill hole. 
     
     
       3. The battery can assembly of  claim 1  further comprising:
 a weld protective backing disposed at least partially on an inner surface of the battery can assembly housing the battery stack, the weld protective backing configured to prevent at least some heat from entering the battery can assembly during a welding process. 
 
     
     
       4. The battery can assembly of  claim 3  wherein the battery stack comprises a localized electrode reduction feature corresponding to the seam around the perimeter of the battery can assembly to increase a gap between the seam around the perimeter and the battery stack. 
     
     
       5. The battery can assembly of  claim 3  wherein the weld protective backing comprises at least one of: a metal material, a ceramic material, or a polymer material. 
     
     
       6. The battery can assembly of  claim 1  further comprising:
 at least one support column located within the battery can assembly comprising a first end and a second end, wherein the first end is connected to the first surface and the second end is connected to the second surface. 
 
     
     
       7. The battery can assembly of  claim 6  wherein the at least one support column further comprises a screw extending through the at least one support column. 
     
     
       8. A battery cell comprising:
 a battery enclosure formed of metal comprising a bottom surface, a top surface, and a wall connecting the bottom surface to the top surface, wherein the wall comprises a weld to form a seam around a perimeter of the battery enclosure; 
 a battery stack enclosed within the battery enclosure; and 
 a plurality of indentations formed on the bottom surface that extend into an interior of the battery enclosure to increase the structural rigidity of the battery enclosure. 
 
     
     
       9. The battery cell of  claim 8  further comprising at least one support column located within the battery enclosure comprising a first end and a second end, wherein the first end is connected to the bottom surface and the second end is connected to the top surface such that the top surface and the bottom surface apply a pressure force to the battery stack. 
     
     
       10. The battery cell of  claim 9  wherein the at least one support column further comprises a screw extending through the at least one support column. 
     
     
       11. The battery cell of  claim 8  further comprising:
 a weld protective backing disposed at least partially on an inner surface of the battery enclosure, the weld protective backing configured to prevent at least some heat from entering the enclosure during a welding process used to make the weld seam. 
 
     
     
       12. The battery cell of  claim 11  wherein the weld protective backing comprises at least one of: a metal material, a ceramic material, or a polymer material. 
     
     
       13. The battery cell of  claim 8  wherein the battery stack comprises a localized electrode reduction feature corresponding to the seam around the perimeter of the battery enclosure to increase a gap between the seam around the perimeter and the battery stack. 
     
     
       14. The battery cell of  claim 8  further comprising an additional plurality of indentations formed on the top surface that further increase the structural rigidity of the battery enclosure. 
     
     
       15. The battery can assembly of  claim 1  wherein a thickness of the second surface is about 100 μm. 
     
     
       16. The battery can assembly of  claim 1  wherein a thickness of the second surface is greater than a thickness of the wall. 
     
     
       17. The battery cell of  claim 8  wherein a thickness of the bottom surface is about 100 μm. 
     
     
       18. The battery cell of  claim 8  wherein a thickness of the bottom surface is greater than a thickness of the wall.